Lens drive apparatus, camera module and camera

ABSTRACT

A lens drive apparatus comprises: an assembly that is formed by assembling a lens holder together with a magnet holder that holds a magnet; a first drive section that displaces the lens holder in a direction of an optical axis in collaboration with the magnet and a first coil; and a second drive section that displaces the assembly in a direction orthogonal to the optical axis in collaboration with the magnet and a second coil, wherein the magnet holder comprises a hollow part that accommodates the magnet at a position facing both of the first coil and the second coil.

CROSS-REFERENCE TO THE RELATED APPLICATION

The present application is a Continuation Application of applicationSer. No. 13/390,603, filed Feb. 15, 2012, which claims priority fromPCT/JP2010/063683, filed Aug. 12, 2010, the contents of which areincorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a camera-shake correction apparatus.and more particularly to a camera-shake correction apparatus thatcorrects camera shake (vibration) that occurs when a still image iscaptured with a small camera for mobile phone use, and enables ablur-free image to be captured.

BACKGROUND OF THE INVENTION

Various camera-shake correction apparatuses (image blurring correctionapparatuses) have hitherto been proposed that enable blurring on animaging surface to be prevented and sharp imaging to be achieved despitethe occurrence of camera shake (vibration) when a still image iscaptured.

Optical methods such as a sensor shifting method and lens shiftingmethod, and software methods in which camera shake is corrected by imageprocessing by means of software, are known as camera-shake correctionmethods.

A sensor shifting method is disclosed in Patent 2004-274242 (PatentLiterature 1), for example. A digital camera disclosed in PatentLiterature 1 has a configuration in which an imaging device (CCD) ismovable centered on a reference position (center) by means of anactuator. The actuator performs camera-shake correction by moving a CCDaccording to camera shake detected by a vibration sensor. The CCD islocated in a CCD moving section. The CCD can be moved by means of theCCD moving section within an XY plane perpendicular to a Z axis. The CCDmoving section comprises three main members: a base plate fixed to ahousing, a first slider that moves in the X-axis direction with respectto the base plate, and a second slider that moves in the Y-axisdirection with respect to the base plate.

In a sensor shifting method such as disclosed in Patent Literature 1,the CCD moving section (movable mechanism) is large. Consequently, it isdifficult to apply a sensor-shifting type of camera-shake correctionapparatus to a small camera for mobile phone use from a size (externalshape and height) standpoint.

Next, lens shifting methods will be described.

Patent 2009-145771 (Patent Literature 2), for example, discloses acamera-shake correction apparatus that includes a camera-shakecorrection unit that drives a corrective lens. The camera-shakecorrection unit is provided with a base plate, which is a fixed member,a movable lens barrel that holds the corrective lens in a movablefashion, three spheres held between the base plate and the movable lensbarrel, a plurality of elastic bodies supporting the movable lens barrelelastically against the base plate, two coils fixed to the base plate,and two magnets fixed to the movable lens barrel.

Also, Patent 2006-65352 (Patent Literature 3) discloses an “imageblurring correction apparatus” that corrects image blurring bycontrolling the movement of a specific lens group (hereinafter referredto as “corrective lens”) in an imaging optical system (image formationoptical system) comprising a plurality of lens groups in two directionsperpendicular to each other in a plane perpendicular to the opticalaxis. In the image blurring correction apparatus disclosed in PatentLiterature 3, the corrective lens is supported so as to be able to movevertically (in the pitch direction) and laterally (in the yaw direction)with respect to a fixed frame via a pitching movement frame and yawingmovement frame.

Patent 2008-26634 (Patent Literature 4) discloses a “camera-shakecorrection unit” that includes a corrective optical member that correctsblurring of an image formed by an imaging optical system by moving in adirection that intersects the optical axis of the imaging opticalsystem. In the case of a corrective optical member disclosed in PatentLiterature 4, a lens holding frame that holds a corrective lens issupported so as to be able to move in the pitch direction and yawdirection with respect to a housing barrel via a pitch slider and yawslider.

Patent 2006-215095 (Patent Literature 5) discloses an “image blurringcorrection apparatus” that can move a corrective lens by means of asmall driving force. and can perform fast and high-precision imageblurring correction. The image blurring correction apparatus disclosedin Patent Literature 5 is provided with a holding frame that holds acorrective lens, a first slider that supports this holding frame so asto be able to slide in a first direction (pitch direction), a secondslider that supports the holding frame so as to be able to slide in asecond direction (yaw direction), a first coil motor that drives thefirst slider in the first direction, and a second coil motor that drivesthe second slider in the second direction.

Patent 2008-15159 (Patent Literature 6) discloses a lens barrel providedwith a camera-shake correction optical system installed so as to be ableto move in a direction perpendicular to the optical axis. In thecamera-shake correction optical system disclosed in Patent Literature 6,a movable VR unit located inside a VR body unit holds a corrective lens(a third lens group), and is installed so as to be able to move withinan XY plane perpendicular to the optical axis.

Patent 2007-212876 (Patent Literature 7) discloses an “image blurringcorrection apparatus” in which image blurring can be corrected by makinga corrective lens held in a movable frame movable in mutuallyperpendicular first and second directions with respect to the opticalaxis of the lens system, and controlling the optical axis of thecorrective lens by means of a drive section so as to coincide with theoptical axis of the lens system.

Patent 2007-17957 (Patent Literature 8) discloses an “image blurringcorrection apparatus” that corrects image blurring by driving acorrective lens for correcting blurring of an image formed by a lenssystem by means of operation of a lens drive section in a firstdirection and second direction that are directions perpendicular to theoptical axis of the lens system and also mutually perpendicular. In theimage blurring correction apparatus disclosed in Patent Literature 8,the lens drive section is provided located toward a directionperpendicular to the optical axis of the corrective lens.

Patent 2007-17874 (Patent Literature 9) discloses an “image blurringcorrection apparatus” in which image blurring can be corrected by makinga corrective lens held in a movable frame movable in a first directionand second direction that are directions perpendicular to the opticalaxis of the lens system and also mutually perpendicular, and controllingthe optical axis of the corrective lens so as to coincide with theoptical axis of the lens system. This image blurring correctionapparatus disclosed in Patent Literature 9 is provided with a drivesection having a coil and magnet that are made movable in a relativefashion. Either the coil or the magnet is fixed to a movable frame, andthe other is fixed to a supporting frame that supports the movable framein a movable fashion. Also, this image blurring correction apparatusdisclosed in Patent Literature 9 is provided with a first Hall devicethat detects position information relating to a first direction of thecorrective lens by detecting magnetic force of the magnet, and a secondHall device that detects position information relating to a seconddirection of the corrective lens by detecting magnetic force of themagnet.

The lens-shifting types of image blurring correction apparatuses(camera-shake correction apparatuses) disclosed in above PatentLiterature 2 through 9 all have a structure whereby a corrective lens isadjusted by being moved in a plane perpendicular to the optical axis.Therefore, a problem with an image blurring correction apparatus(camera-shake correction apparatus) having such a structure is that itsstructure is complex and it is not suitable for miniaturization. That isto say, as with an above-described sensor-shifting type of camera-shakecorrection apparatus, it is difficult to apply a lens-shifting type ofcamera-shake correction apparatus to a small camera for mobile phone usefrom a size (external shape and height) standpoint.

A software method is disclosed, for example, in Patent HEI11-64905(Patent Literature 10). In the method disclosed in Patent Literature 10,a captured image is made static when an imaging apparatus becomes staticand free from camera shake by eliminating a noise component fromdetection section detection results, and calculating specificinformation necessary for correction of image blurring due to shaking ofthe imaging apparatus from a detection signal from which this noisecomponent has been eliminated.

However, a problem with this software method disclosed in PatentLiterature 10 is that image quality degrades in comparison with anabove-described optical method. Also, a software method has thedisadvantage of taking a long time, since it includes both imaging timeand software processing time.

In order to solve the above problems, a camera-shake correctionapparatus (image blurring correction apparatus) has been proposed thatcorrects camera shake (image blurring) by shaking an actual lens module(camera module) that holds a lens and imaging device (image sensor).Such a method will be referred to here as an “optical unit tiltingmethod.”

“Optical unit tilting methods” will now be described.

Patent 2007-41455 (Patent Literature 11), for example, discloses an“optical apparatus image blurring correction apparatus” that is providedwith a lens module that holds a lens and imaging device, a framestructure that supports this lens module so as to be rotatable by meansof a rotation shaft, a drive section (actuator) that rotates the lensmodule with respect to the frame structure by providing driving force toa driven section (rotor) of the rotation shaft, and a force applicationsection (leaf spring) that forces the drive section (actuator) againstthe driven section (rotor) of the rotation shaft. The frame structurecomprises an inner frame and outer frame. The drive section (actuator)is disposed so as to come into contact with the driven section (rotor)of the rotation shaft from a direction perpendicular to the opticalaxis. The drive section (actuator) comprises a piezoelectric device anda rotation-shaft-side operating section. The operating section drivesthe rotation shaft by means of vertical oscillation and flexionoscillation of the piezoelectric device.

Also, Patent 2007-93953 (Patent Literature 12) discloses a “camera-shakecorrection apparatus” in which a camera module integrating an imaginglens and image sensor is housed in a housing, and the camera module ispivoted in the housing so as to be able to rock freely about a firstshaft and second shaft that are perpendicular to the imaging opticalaxis and intersect each other at right angles, and camera shake duringstill image capture is corrected by controlling the overall attitude ofthe camera module within the housing according to shaking of the housingdetected by a camera-shake sensor. The camera-shake correction apparatusdisclosed in Patent Literature 12 is provided with a center frame thatsupports the inner frame to which the camera module is fixed so as to beable to rock freely about the first shaft from the outside thereof, anouter frame that is fixed to the housing and supports the center frameso as to be able to rock about the second shaft from the outsidethereof, a first drive section that is incorporated into the centerframe and rocks the inner frame about the first shaft according to acamera-shake signal from a camera-shake sensor (first sensor module thatdetects camera shake in the pitch direction), and a second drive sectionthat is incorporated into the outer frame and rocks the center frameabout the second shaft according to a camera-shake signal from acamera-shake sensor (second sensor module that detects camera shake inthe yaw direction). The first drive section comprises a first steppingmotor, a first reduction gear train that decelerates the rotationthereof, and a first cam that rotates integrally with a final gear androcks the inner frame via a first cam follower provided on the innerframe. The second drive section comprises a second stepping motor, asecond reduction gear train that decelerates the rotation thereof, and asecond cam that rotates integrally with a final gear and rocks thecenter frame via a second cam follower provided on the center frame.

Furthermore, Patent 2009-288770 (Patent Literature 13) discloses an“imaging optical apparatus” capable of dependably correcting shaking byimproving the configuration of an imaging unit drive mechanism for shakecorrection for the imaging unit. The imaging optical apparatus disclosedin Patent Literature 13 comprises, on the inside of a fixed cover, animaging unit (movable module), and a shake correction mechanism forperforming shake correction by displacing this imaging unit. The imagingunit is for moving a lens in the optical axis direction. The imagingunit comprises a movable body that holds a lens and fixed diaphragm onthe inside, a lens drive mechanism that moves this movable body in theoptical axis direction, and a support on which the lens drive mechanismand movable body are mounted. The lens drive mechanism is provided witha lens drive coil, lens drive magnet, and yoke. The imaging unit issupported by a fixed body by means of four suspension wires. At twoplaces on either side of the optical axis are provided a first imagingunit drive mechanism and second imaging unit drive mechanism for shakecorrection, the two of which form a pair. In these imaging unit drivemechanisms, an imaging unit drive magnet is held on the movable bodyside, and an imaging unit drive coil is held on the fixed body side.

Patent 2007-142938 (Patent Literature 14) discloses a portableinformation terminal having a function for correcting camera shakeduring imaging using a gyroscope or suchlike angular velocity sensor. Inorder to perform correction of captured image shake, it is necessary toset a reference pitch axis and yaw axis that are mutually perpendicularin a plane that is perpendicular to the optical axis of a camera lens,and detect the angular velocity of both rotation with the pitch axis asthe central axis of rotation and rotation with the yaw axis as thecentral axis of rotation. Patent Literature 14 discloses the dispositionof a first gyroscope that detects the rotational angular velocity ofrotation about the pitch axis, and a second gyroscope that detects therotational angular velocity of rotation about the yaw axis, on a sidesurface of an imaging apparatus.

Also, Patent 2008-20668 (Patent Literature 15) discloses a lens driveapparatus that drives a lens in the optical axis direction. This lensdrive apparatus disclosed in Patent Literature 15 is provided with aplurality of coiled bodies fixed to the outer periphery of a lenssupport, and a magnet section disposed facing the coiled bodies. Themagnet section is provided with magnetic poles N and S that arepolarized into an N pole and S pole in a radial direction and differ inthe lens optical axis direction. The coiled bodies are providedcorresponding to the polarity of the magnet section, and currents flowin mutually opposite directions in adjacent coiled bodies.

CITATION LIST Patent Literature

PTL 1

Patent 2004-274242

PTL 2

Patent 2009-145771

PTL 3

Patent 2006-65352

PTL 4

Patent 2008-26634

PTL 5

Patent 2006-215095

PTL 6

Patent 2008-15159

PTL 7

Patent 2007-212876

PTL 8

Patent 2007-17957

PTL 9

Patent 2007-17874

PTL 10

Patent HEI11-64905

PTL 11

Patent 2007-41455

PTL 12

Patent 2007-93953

PTL 13

Patent 2009-288770 (FIG. 1 through FIG. 5)

PTL 14

Patent 2007-142938 (Paragraph 0005, Paragraph 0006, FIG. 2)

PTL 15

Patent 2008-20668

SUMMARY OF INVENTION Technical Problem

The “sensor-shifting” camera-shake correction apparatus disclosed inabove Patent Literature 1 has a large CCD moving section (movablemechanism), and is therefore difficult to apply to a small camera formobile phone use from a size (external shape and height) standpoint.

On the other hand, the “lens-shifting” image blurring correctionapparatuses (camera-shake correction apparatuses) disclosed in abovePatent Literature 2 through 9 all have a structure whereby a correctivelens is adjusted by being moved in a plane perpendicular to the opticalaxis, and there is therefore a problem in that their structure iscomplex and is not suitable for miniaturization.

The “software-type” camera-shake correction method disclosed in PatentLiterature 10 has a problem of image quality degrading in comparisonwith an optical type, and also has the disadvantage of taking a longtime, since it includes both imaging time and software processing time.

On the other hand, the “optical-unit-tilting” image blurring correctionapparatus disclosed in Patent Literature 11 requires the lens module tobe covered with a frame structure comprising an inner frame and outerframe. Also, the “optical-unit-tilting” image blurring correctionapparatus disclosed in Patent Literature 12 requires the camera moduleto be covered with an inner frame, center frame, and outer frame. As aresult, the camera-shake correction apparatus is large in size.Furthermore, with an “optical unit tilting method,” there is a rotationshaft, and there is consequently also a problem of the occurrence offriction between a hole and shaft, and the occurrence of hysteresis. The“optical-unit-tilting” imaging optical apparatus disclosed in PatentLiterature 13 requires a magnet for imaging unit drive in addition to amagnet for lens drive. As a result, there is a problem of the imagingoptical apparatus being large in size.

The portable information terminal disclosed in Patent Literature 14 onlydiscloses the use of an angular velocity sensor such as a gyroscope as acamera-shake sensor.

Also, Patent Literature 15 simply discloses a lens drive apparatus thatdrives a lens in the optical axis direction.

Therefore, the technical problem to be solved by the present inventionis to provide a small, low-profile camera-shake correction apparatus.

Other objects of the present invention will become clear as thedescription proceeds.

Solution to Problem

To state the main point of a typical aspect of the present invention, acamera-shake correction apparatus corrects camera shake by moving all ora moving part of an auto-focusing lens drive apparatus for moving a lensbarrel along the optical axis, in a first direction and a seconddirection that are perpendicular to the optical axis and areperpendicular to each other. The auto-focusing lens drive apparatus isprovided with a focusing coil and a permanent magnet that is disposed onthe radial-direction outside of this focusing coil with respect to theoptical axis and facing the focusing coil. According to a typical aspectof the present invention, a camera-shake correction apparatus has: abase that is disposed so as to be spaced from the bottom surface of theauto-focusing lens drive apparatus; a plurality of suspension wires thateach have one end fixed to the outer peripheral section of this base,that extend along the optical axis, and that support the entireauto-focusing lens drive apparatus or a moving part thereof so as to beable to rock in the first direction and the second direction; and acamera-shake correction coil disposed so as to face the permanentmagnet.

Advantageous Effects of Invention

The present invention uses a permanent magnet of an auto-focusing lensdrive apparatus in common with that of a camera-shake correctionapparatus, enabling a small size and low profile to be achieved.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an exploded oblique view of a camera-shake correctionapparatus according to a first embodiment of the present invention;

FIG. 2 is an exploded oblique view of auto-focusing lens drive apparatus20 used in the camera-shake correction apparatus shown in FIG. 1;

FIG. 3 is an assembled oblique view, excluding the cover, of thecamera-shake correction apparatus shown in FIG. 1;

FIG. 4 is a block diagram showing the configuration of a camera-shakecorrection actuator that controls the camera-shake correction apparatusshown in FIG. 1 through FIG. 3;

FIG. 5 is an external oblique view of a camera-shake correctionapparatus according to a second embodiment of the present invention;

FIG. 6 is a vertical cross-sectional view of the camera-shake correctionapparatus shown in FIG. 5;

FIG. 7 is an exploded oblique view of the camera-shake correctionapparatus shown in FIG. 5;

FIG. 8 is an exploded oblique view of an auto-focusing lens driveapparatus used in the camera-shake correction apparatus shown in FIG. 5;

FIG. 9 is an oblique view of a magnetic circuit used in the camera-shakecorrection apparatus shown in FIG. 6 and FIG. 7;

FIG. 10 is a vertical cross-sectional view of the magnetic circuit shownin FIG. 9;

FIG. 11 is a plan view with four first permanent magnet sections and afirst focusing coil omitted from the magnetic circuit shown in FIG. 9;

FIG. 12 is an external oblique view of a camera-shake correctionapparatus according to a third embodiment of the present invention;

FIG. 13 is a vertical cross-sectional view of the camera-shakecorrection apparatus shown in FIG. 12;

FIG. 14 is an exploded oblique view of the camera-shake correctionapparatus shown in FIG. 12;

FIG. 15 is an exploded oblique view of a movable section of anauto-focusing lens drive apparatus used in the camera-shake correctionapparatus shown in FIG. 12;

FIG. 16 is a plan view of a position information section of a positiondetection section used in the camera-shake correction apparatus in FIG.12; and

FIG. 17 is a vertical cross-sectional view of a sample variant using anoptical position detection section as a position detection section inthe camera-shake correction apparatus shown in FIG. 6.

DESCRIPTION OF EMBODIMENTS

Now, embodiments of the present invention will be described withreference to the accompanying drawings.

Camera-shake correction apparatus 10 according to a first embodiment ofthe present invention will now be described with reference to FIG. 1through FIG. 3. FIG. 1 is an exploded oblique view of camera-shakecorrection apparatus 10. FIG. 2 is an exploded oblique view ofauto-focusing lens drive apparatus 20 used in camera-shake correctionapparatus 10 shown in FIG. 1. FIG. 3 is an assembled oblique view,excluding shield cover 42, of camera-shake correction apparatus 10 shownin FIG. 1.

Here, orthogonal coordinate system (X,Y,Z) is used, as shown in FIG. 1through FIG. 3. In the states illustrated in FIG. 1 through FIG. 3, inorthogonal coordinate system (X,Y,Z), the X-axis direction is thefront-back direction (depth direction), the Y-axis direction is thehorizontal direction (width direction), and the Z-axis direction is thevertical-direction (height direction). In the examples shown in FIG. 1through FIG. 3, vertical direction Z is the lens optical axis Odirection. In this first embodiment, the X-axis direction (front-backdirection) is also referred to as the first direction, and the Y-axisdirection (horizontal direction) is also referred to as the seconddirection.

In an actual usage situation, the optical axis O direction—that is, theZ-axis direction—is the front-back direction. In other words, the upwardZ-axis direction is the forward direction, and the downward Z-axisdirection is the rearward direction.

Camera-shake correction apparatus 10 illustrated is an apparatus thatcorrects camera shake (vibration) that occurs when a still image iscaptured with a small camera for mobile phone use, and enables ablur-free image to be captured. Camera-shake correction apparatus 10corrects camera shake by moving the entirety of auto-focusing lens driveapparatus 20 in first direction (front-back direction) X and seconddirection (horizontal direction) Y that are perpendicular to opticalaxis O and are perpendicular to each other.

Auto-focusing lens drive apparatus 20 is for moving lens barrel 12 alongoptical axis O. Base printed wiring board (base) 14 is disposed so as tobe spaced from the bottom surface of auto-focusing lens drive apparatus20. Although not illustrated, an imaging device disposed on an imagingboard is mounted on the bottom (rear part) of this base printed wiringboard 14. This imaging device captures a subject image formed by meansof lens barrel 12, and converts this subject image to an electricalsignal. The imaging device comprises, for example, a CCD (charge coupleddevice) image sensor, CMOS (complementary metal oxide semiconductor)image sensor, or the like. Therefore, a camera module is configured bycombining lens drive apparatus 20, an imaging board, and an imagingdevice.

Auto-focusing lens drive apparatus 20 will now be described withreference to FIG. 2.

Auto-focusing lens drive apparatus 20 is provided with lens holder 24having tubular section 240 for holding lens barrel 12, focusing coil 26fixed to this lens holder 24 so as to be positioned around tubularsection 240, magnet holder 30 that holds permanent magnet 28 disposed onthe outside of this focusing coil 26, facing focusing coil 26, and apair of leaf springs 32 and 34 provided on either side of optical axis Oof tubular section 240 of lens holder 24. The pair of leaf springs 32and 34 support lens holder 24 so as to be displaceable in the opticalaxis O direction when lens holder 24 is positioned in a radialdirection. Of the pair of leaf springs 32 and 34, leaf spring 32 isreferred to as the upper leaf spring, and leaf spring 34 is referred toas the lower leaf spring.

As stated above, in an actual usage situation, the upward Z-axisdirection (optical axis O direction) is the forward direction, and thedownward Z-axis direction (optical axis O direction) is the rearwarddirection. Therefore, upper leaf spring 32 is also referred to as thefront spring, and lower leaf spring 34 is also referred to as the rearspring.

Magnet holder 30 is of octagonally tubular shape. That is to say, magnetholder 30 has octagonally tubular outer tube section 302, octagonalupper ring-shaped end section 304 provided on the top (front) of thisouter tube section 302, and octagonal lower ring-shaped end 306 providedon the bottom (rear) of outer tube section 302. Upper ring-shaped endsection 304 has eight upper projections 304 a projecting upward, andlower ring-shaped end 306 has eight lower projections 306 a projectingdownward.

Focusing coil 26 is of octagonally tubular shape matching the shape ofoctagonally tubular magnet holder 30. Permanent magnet 28 includes fourpermanent magnet sections 282 disposed on octagonally tubular outer tubesection 302 of magnet holder 30 so as to be spaced from each other infirst direction (front-back direction) X and second direction(horizontal direction) Y. In any event, permanent magnet 28 is disposedspaced from focusing coil 26.

Upper leaf spring (front spring) 32 is disposed above (forward) in theoptical axis O direction in lens holder 24, and lower leaf spring (rearspring) 34 is disposed below (rearward) in the optical axis O directionin lens holder 24. Upper leaf spring (front spring) 32 and lower leafspring (rear spring) 34 have almost identical configurations.

Upper leaf spring (front spring) 32 has upper inner ring section 322attached to the top of lens holder 24, and upper outer ring section 324attached to upper ring-shaped end section 304 of magnet holder 30. Fourupper arm sections 326 are provided between upper inner ring section 322and upper outer ring section 324. That is to say, four upper armsections 326 link upper inner ring section 322 and upper outer ringsection 324.

Upper outer ring section 324 has eight engaging notches 324 a thatengage respectively with eight upper projections 304 a of magnet holder30. Ring-shaped upper printed wiring board (upper board) 36 is disposedon the top of upper leaf spring (front spring) 32. Upper printed wiringboard (upper board) 36 has eight upper board holes 36 a into which eightupper projections 304 a of magnet holder 30 are pressed (inserted)respectively. That is to say, eight upper projections 304 a of magnetholder 30 are pressed (inserted) respectively into eight upper boardholes 36 a of ring-shaped upper printed wiring board (upper board) 36via eight engaging notches 324 a of upper outer ring section 324. Thatis to say, upper outer ring section 324 of upper leaf spring (frontspring) 32 is fixed by being sandwiched between upper ring-shaped endsection 304 of magnet holder 30 and ring-shaped upper printed wiringboard 36.

Similarly, lower leaf spring (rear spring) 34 has a lower inner ringsection (not illustrated) attached to the bottom of lens holder 24, andlower outer ring section 344 attached to lower ring-shaped end 306 ofmagnet holder 30. Four lower arm sections (not illustrated) are providedbetween the lower inner ring section and lower outer ring section 344.That is to say, four lower arm sections link the lower inner ringsection and lower outer ring section 344.

Lower outer ring section 344 has eight lower engaging notches 344 a thatengage respectively with eight lower projections 306 a of magnet holder30. Ring-shaped stopper 38 is disposed on the bottom of lower leafspring (rear spring) 34. Stopper 38 has eight stopper notches 38 a intowhich eight lower projections 306 a of magnet holder 30 are pressed(inserted) respectively. That is to say, eight lower projections 306 aof magnet holder 30 are pressed (inserted) respectively into eightstopper notches 38 a of stopper 38 via eight engaging notches 344 a oflower outer ring section 344. That is to say, lower outer ring section344 of lower leaf spring (rear spring) 34 is fixed by being sandwichedbetween lower ring-shaped end 306 of magnet holder 30 and stopper 38.

The elastic members comprising upper leaf spring 32 and lower leafspring 34 function as guide sections that guide lens holder 24 so as tobe able to move only in the optical axis O direction. Upper leaf spring32 and lower leaf spring 34 are made of beryllium copper, phosphorbronze, or the like.

Internal thread 242 is cut into the inner peripheral wall of tubularsection 240 of lens holder 24, and external thread 122 that is screwedinto above internal thread 242 is cut into the outer peripheral wall oflens barrel 12. Therefore, to fit lens barrel 12 into lens holder 24,lens barrel 12 is accommodated inside lens holder 24 by turning lensbarrel 12 about optical axis O and screwing lens barrel 12 into tubularsection 240 of lens holder 24 in the optical axis O direction, and theyare joined together by means of adhesive or the like.

By passing a current through focusing coil 26, it is possible to adjustthe position of lens holder 24 (lens barrel 12) in the optical axis Odirection through the mutual action of the magnetic field of permanentmagnet 28 and a magnetic field by the current flowing through focusingcoil 26.

Camera-shake correction apparatus 10 will now be described withreference to FIG. 1 and. FIG. 3.

Camera-shake correction apparatus 10 has four suspension wires 16 thateach have one end fixed to one of the four corners of base printedwiring board (base) 14, and camera-shake correction coils 18 disposed onthe outside of permanent magnet 28 of above auto-focusing lens driveapparatus 20, facing permanent magnet 28.

Four suspension wires 16 extend along optical axis O, and support theentirety of auto-focusing lens drive apparatus 20 so as to be able torock in first direction (front-back direction) X and second direction(horizontal direction) Y. The other ends of four suspension wires 16 arefixed to upper printed wiring board 36 of above auto-focusing lens driveapparatus 20. To be precise, upper printed wiring board 36 has four wirefixing holes 36 b into which the other ends of four suspension wires 16are inserted. The other ends of four suspension wires 16 are insertedinto these four wire fixing holes 36 b, and are fixed with adhesive,solder, or the like.

Two of four suspension wires 16 are used to supply power to focusingcoil 26.

As described above, permanent magnet 28 includes four permanent magnetsections 282 disposed so as to face each other in first direction(front-back direction) X and second direction (horizontal direction) Y.

Camera-shake correction apparatus 10 is provided with four coil boards40 disposed so as to face and be spaced from four permanent magnetsections 282 respectively. Above camera-shake correction coils 18 areformed on these four coil boards 40.

To be precise, a pair of camera-shake correction coils 18 are formed ateither end of each coil board 40. Therefore, there are a total of eightcamera-shake correction coils 18.

Four camera-shake correction coils 18 formed on two coil boards 40disposed so as to face each other in second direction (horizontaldirection) Y are for moving (rocking) auto-focusing lens drive apparatus20 in first direction (front-back direction) X.

These four camera-shake correction coils 18 are referred to asfirst-direction actuator 18 (1).

On the other hand, four camera-shake correction coils 18 formed on twocoil boards 40 disposed so as to face each other in first direction(front-back direction) X are for moving (rocking) auto-focusing lensdrive apparatus 20 in second direction (horizontal direction) Y. Thesefour camera-shake correction coils 18 are referred to assecond-direction actuator 18 (2).

In any event, camera-shake correction coils 18 are for driving theentirety of auto-focusing lens drive apparatus 20 in the X-axisdirection (first direction) and Y-axis direction second direction) incollaboration with permanent magnet 28. Also, the combination ofcamera-shake correction coils 18 and permanent magnet 28 functions as avoice coil motor (VCM).

Thus, camera-shake correction apparatus 10 illustrated corrects camerashake by moving lens barrel 12 itself, housed in auto-focusing lensdrive apparatus 20, in first direction (front-back direction) X andsecond direction (horizontal direction) Y. Therefore, camera-shakecorrection apparatus 10 is referred to as a “barrel-shifting”camera-shake correction apparatus.

Camera-shake correction apparatus 10 is also provided with shield cover42 that includes square tubular section 422 covering four coil boards40. In the example illustrated, four coil boards 40 are attached to theinner wall of square tubular section 422 of shield cover 42 as shown inFIG. 1.

Camera-shake correction apparatus 10 illustrated is also provided withposition detection section 50 for detecting the position ofauto-focusing lens drive apparatus 20 with respect to base printedwiring board 14. Position detection section 50 illustrated comprisesfour Hall devices 50 mounted on base printed wiring board 14. These fourHall devices 50 are disposed facing and spaced from four permanentmagnet sections 282.

A pair of Hall devices 50 disposed facing in first direction (front-backdirection) X detect a first position associated with first direction(front-back direction) X movement (rocking) by detecting magnetic forceof a pair of permanent magnet sections 282 facing them. A pair of Halldevices 50 disposed facing in second direction (horizontal direction) Ydetect a second position associated with second direction (horizontaldirection) Y movement (rocking) by detecting magnetic force of a pair ofpermanent magnet sections 282 facing them.

FIG. 4 is a block diagram showing the configuration of camera-shakecorrection actuator 600 that controls camera-shake correction apparatus10. Camera-shake correction apparatus 10 is installed in acamera-equipped mobile phone (not illustrated).

The housing of a camera-equipped mobile phone (not illustrated) isprovided with first-direction gyroscope 602 for detecting firstdirection (front-back direction) X shake, and second-direction gyroscope604 for detecting second direction (horizontal direction) Y shake.

First-direction gyroscope 602 detects first direction (front-backdirection) X angular velocity, and outputs a first angular velocitysignal representing the detected first direction (front-back direction)X angular velocity. Second-direction gyroscope 604 detects seconddirection (horizontal direction) Y angular velocity, and outputs asecond angular velocity signal representing the detected seconddirection (horizontal direction) Y angular velocity. The first andsecond angular velocity signals are supplied to shake correction controlsection 606. A shutter operation command signal is supplied to shakecorrection control section 606 from shutter button 608.

Shake correction control section 606 has shake detection circuit 612that detects shake of the camera-equipped mobile phone housing from thefirst and second angular velocity detection signals, and sequencecontrol circuit 614 that receives a shutter operation command signal.Shake detection circuit 612 includes a filter circuit and amplifiercircuit. Shake detection circuit 612 supplies a shake detection signalto shake amount detection circuit 616. Shake amount detection circuit616 detects a shake amount of the camera-equipped mobile phone housingfrom the shake detection signal, and sends a shake amount detectionsignal to coefficient conversion circuit 618. Coefficient conversioncircuit 618 performs coefficient conversion of the shake amountdetection signal, and sends a coefficient-converted signal to controlcircuit 620. A position detection signal from position detection section(position sensor) 50 provided in camera-shake correction apparatus 10 issupplied to this control circuit 620.

In response to the coefficient-converted signal, control circuit 620outputs a control signal so as to cancel out shake detected by shakedetection circuit 612 based on the position detection signals. Inresponse to a shutter operation command signal, sequence control circuit614 controls the timing of shake amount detection circuit 616,coefficient conversion circuit 618, and control circuit 620. The controlsignal is supplied to drive circuit 622.

As stated earlier, camera-shake correction apparatus 10 is provided withfirst-direction actuator 18 (1) for moving (rocking) the entirety ofauto-focusing lens drive apparatus 20 in first direction (front-backdirection) X, and second-direction actuator 18 (2) for moving (rocking)the entirety of auto-focusing lens drive apparatus 20 in seconddirection (horizontal direction) Y, as voice coil motors. In any event,camera-shake correction apparatus 10 includes first-direction actuator18 (1) and second-direction actuator 18 (2).

Drive circuit 622 drives first-direction actuator 18 (1) andsecond-direction actuator 18 (2) in response to a control signal.

By means of such a configuration, camera-shake correction apparatus 10can move (rock) the entirety of auto-focusing lens drive apparatus 20 soas to cancel out shake of a camera-equipped mobile phone housing. As aresult, camera shake can be corrected.

Camera-shake correction apparatus 10 according to a first embodiment ofthe present invention as described above achieves the following effects.

Since auto-focusing lens drive apparatus 20 is provided withcamera-shake correction apparatus 10, and permanent magnet 28 is used incommon, the number of component parts can be reduced. As a result, thesize (mainly the height) of camera-shake correction apparatus 10 can bemade smaller (lower).

In an optical unit tilting type of camera-shake correction apparatus,there is a rotation shaft, and consequently friction occurs between ahole and shaft, resulting in the occurrence of hysteresis. In contrast,in camera-shake correction apparatus 10 according to this firstembodiment, the entirety of auto-focusing lens drive apparatus 20 issupported mechanically by four suspension wires 16, making hysteresisunlikely to occur.

Compared with camera-shake correction apparatuses using conventionaloptical camera-shake correction methods (lens shifting, sensor shifting,or optical unit tilting), the use of a barrel-shifting method enablesthe size (mainly the height) of camera-shake correction apparatus 10 tobe made virtually the same that of auto-focusing lens drive apparatus20. As a result, it is possible for camera-shake correction apparatus 10according to this first embodiment to be installed in an opticalcamera-shake correcting camera for mobile phone use.

In this first embodiment, a magnetic position detection sectioncomprising Hall devices 50 is used as a position detection section(position sensor), but another position detection section (positionsensor) such as a photoreflector or suchlike optical position detectionsection may be used instead of Hall devices 50.

Also, in the above-described first embodiment, permanent magnet 28comprises four permanent magnet sections 282 disposed so as to face eachother in first direction X and second direction Y, but the number ofpermanent magnet sections is not limited to four, and, for example,eight sections may be used that are disposed facing in diagonaldirections rather than in only a first and second direction. In thiscase, the number of camera-shake correction coils 18 and the number ofcoil boards 40 are also changed in line with the number of permanentmagnet sections 288. Furthermore, in the above-described firstembodiment, one end of each of four suspension wires 16 is fixed to oneof the four corners of base 14, but these ends may also be fixed to theouter periphery of base 14. Moreover, the number of suspension wires 16is not limited to four, and may be any plurality.

Camera-shake correction apparatus 10A according to a second embodimentof the present invention will now be described with reference to FIG. 5through FIG. 8. FIG. 5 is an external oblique view of camera-shakecorrection apparatus 10A. FIG. 6 is a vertical cross-sectional view ofcamera-shake correction apparatus 10A. FIG. 7 is an exploded obliqueview of camera-shake correction apparatus 10A. FIG. 8 is an explodedoblique view of auto-focusing lens drive apparatus 20A used incamera-shake correction apparatus 10A shown in FIG. 5.

Here, orthogonal coordinate system (X,Y,Z) is used, as shown in FIG. 5through FIG. 8. In the states illustrated in FIG. 5 through FIG. 8, inorthogonal coordinate system (X,Y,Z), the X-axis direction is thefront-back direction (depth direction), the Y-axis direction is thehorizontal direction (width direction), and the Z-axis direction is thevertical-direction (height direction). In the examples shown in FIG. 5through FIG. 8, vertical direction Z is the lens optical axis Odirection. In this second embodiment, the X-axis direction (front-backdirection) is also referred to as the first direction, and the Y-axisdirection (horizontal direction) is also referred to as the seconddirection.

In an actual usage situation, the optical axis O direction—that is, theZ-axis direction—is the front-back direction. In other words, the upwardZ-axis direction is the forward direction, and the downward Z-axisdirection is the rearward direction.

Camera-shake correction apparatus 10A illustrated is an apparatus thatcorrects camera shake (vibration) that occurs when a still image iscaptured with a small camera for mobile phone use, and enables ablur-free image to be captured. Camera-shake correction apparatus 10Acorrects camera shake by moving the entirety of auto-focusing lens driveapparatus 20A in first direction (front-back direction) X and seconddirection (horizontal direction) Y that are perpendicular to opticalaxis O and are perpendicular to each other.

Auto-focusing lens drive apparatus 20A is for moving lens barrel 12Aalong optical axis O. Base 14A is disposed so as to be spaced from thebottom surface of auto-focusing lens drive apparatus 20A. Although notillustrated, an imaging device disposed on an imaging board is mountedon the bottom (rear part) of this base 14A. This imaging device capturesa subject image formed by means of lens barrel 12A, and converts thissubject image to an electrical signal. The imaging device comprises, forexample, a CCD (charge coupled device) image sensor, CMOS (complementarymetal oxide semiconductor) image sensor, or the like. Therefore, acamera module is configured by combining lens drive apparatus 20A, animaging board, and an imaging device.

Base 14A comprises ring-shaped base section 142A of square externalshape and having a circular aperture inside, and square-tube-shapedtubular section 144A that projects in the upward optical axis Odirection from the outer edge of this base section 142A.

Camera-shake correction apparatus 10A has four suspension wires 16A thateach have one end fixed to one of the four corners of base section 142Aof base 14A, and camera-shake correction coils 18A disposed so as toface permanent magnet 28A of auto-focusing lens drive apparatus 20Adescribed later herein in a manner described later herein.

Four suspension wires 16A extend along optical axis O, and support theentirety of auto-focusing lens drive apparatus 20A so as to be able torock in first direction (front-back direction) X and second direction(horizontal direction) Y. The other ends of four suspension wires 16Aare fixed to the upper end of above auto-focusing lens drive apparatus20A as described later herein.

As described later herein, camera-shake correction apparatus 10A isprovided with one square-ring-shaped coil board 40A disposed so as toface and be spaced from permanent magnet 28A. This coil board 40A isattached to the upper end of tubular section 144A of base 14A. Abovecamera-shake correction coils 18A are formed on this coil board 40A.

Auto-focusing lens drive apparatus 20A will now be described withreference to FIG. 8.

Auto-focusing lens drive apparatus 20A is provided with lens holder 24Ahaving tubular section 240A for holding lens barrel 12A, first andsecond focusing coils 26A-1 and 26A-2 fixed to this lens holder 24A soas to be positioned around tubular section 240A, magnet holder 30A thatholds permanent magnet 28A disposed on the outside of first and secondfocusing coils 26A-1 and 26A-2, facing first and second focusing coils26A-1 and 26A-2, and a pair of leaf springs 32A and 34A provided oneither side of optical axis O of tubular section 240A of lens holder24A.

First focusing coil 26A-1 is installed in the upper optical axis Odirection of tubular section 240A of lens holder 24A, and secondfocusing coil 26A-2 is installed in the lower optical axis O directionof tubular section 240A of lens holder 24A.

The pair of leaf springs 32A and 34A support lens holder 24A so as to bedisplaceable in the optical axis O direction when lens holder 24A ispositioned in a radial direction. Of the pair of leaf springs 32A and34A, leaf spring 32A is referred to as the upper leaf spring, and leafspring 34A is referred to as the lower leaf spring.

As stated above, in an actual usage situation, the upward Z-axisdirection (optical axis O direction) is the forward direction, and thedownward Z-axis direction (optical axis O direction) is the rearwarddirection. Therefore, upper leaf spring 32A is also referred to as thefront spring, and lower leaf spring 34A is also referred to as the rearspring.

Magnet holder 30A is of octagonally tubular shape. That is to say,magnet holder 30A has octagonally tubular outer tube section 302A,square upper ring-shaped end section 304A provided on the top (front) ofthis outer tube section 302A, and octagonal lower ring-shaped end 306Aprovided on the bottom (rear) of outer tube section 302A.

First and second focusing coils 26A-1 and 26A-2 are each of octagonallytubular shape matching the shape of octagonally tubular magnet holder30A. Permanent magnet 28A comprises eight rectangular permanent magnetsections disposed on octagonally tubular outer tube section 302A ofmagnet holder 30 a so as to be spaced from each other in first direction(front-back direction) X, second direction (horizontal direction) Y, andvertical direction Z. Of these eight rectangular permanent magnetsections, four first permanent magnet sections 282A-1 are disposed inthe upper optical axis O direction of outer tube section 302A, andremaining four second permanent magnet sections 282A-2 are disposed inthe lower optical axis O direction of outer tube section 302A. Fourfirst permanent magnet sections 282A-1 are disposed spaced from firstfocusing coil 26A-1, and four second permanent magnet sections 282A-2are disposed spaced from second focusing coil 26A-2.

Upper leaf spring (front spring) 32A is disposed above (forward) in theoptical axis O direction in lens holder 24A, and lower leaf spring (rearspring) 34A is disposed below (rearward) in the optical axis O directionin lens holder 24A. Upper leaf spring (front spring) 32A and lower leafspring (rear spring) 34A have almost identical configurations.

Upper leaf spring (front spring) 32A has upper inner ring section 322Aattached to the top of lens holder 24A, and upper outer ring section324A attached to upper ring-shaped end section 304A of magnet holder30A. Four upper arm sections 326A are provided between upper inner ringsection 322A and upper outer ring section 324A. That is to say, fourupper arm sections 326A link upper inner ring section 322A and upperouter ring section 324A.

Upper outer ring section 324A has four wire fixing holes 324Aa intowhich the other ends of above four suspension wires 16A are inserted.

Similarly, lower leaf spring (rear spring) 34A has lower inner ringsection 342A attached to the bottom of lens holder 24A, and lower outerring section 344A attached to lower ring-shaped end 306A of magnetholder 30A. Four lower arm sections 346A are provided between lowerinner ring section 342A and upper outer ring section 344A. That is tosay, four lower arm sections 346A link lower inner ring section 342A andlower outer ring section 344A.

The elastic members comprising upper leaf spring 32A and lower leafspring 34A function as guide sections that guide lens holder 24A so asto be able to move only in the optical axis O direction. Upper leafspring 32A and lower leaf spring 34A are made of beryllium copper,phosphor bronze, or the like.

An internal thread (not illustrated) is cut into the inner peripheralwall of tubular section 240A of lens holder 24A, and an external thread(not illustrated) that is screwed into the above internal thread is cutinto the outer peripheral wall of lens barrel 12A. Therefore, to fitlens barrel 12A into lens holder 24A, lens barrel 12A is accommodatedinside lens holder 24A by turning lens barrel 12A about optical axis Oand screwing lens barrel 12A into tubular section 240A of lens holder24A in the optical axis O direction, and they are joined together bymeans of adhesive or the like.

By passing first and second auto-focusing (AF) currents through firstand second focusing coils 26A-1 and 26A-2 respectively as describedlater herein, it is possible to adjust the position of lens holder 24A(lens barrel 12A) in the optical axis O direction through the mutualaction of the magnetic field of permanent magnet 28A and magnetic fieldsby the AF currents flowing through first and second focusing coils 26A-1and 26A-2.

Camera-shake correction apparatus 10A will now be described in furtherdetail with reference to FIG. 6 and FIG. 7.

As stated earlier, camera-shake correction apparatus 10A has foursuspension wires 16A that each have one end fixed to one of the fourcorners of base section 142A of base 14A, and camera-shake correctioncoils 18A disposed on the outside of permanent magnet 28A of aboveauto-focusing lens drive apparatus 20A, facing permanent magnet 28A.

Four suspension wires 16A extend along optical axis O, and support theentirety of auto-focusing lens drive apparatus 20A so as to be able torock in first direction (front-back direction) X and second direction(horizontal direction) Y. The other ends of four suspension wires 16Aare fixed to the top of above auto-focusing lens drive apparatus 20A.

To be precise, as stated earlier, upper outer ring section 324A has fourwire fixing holes 324Aa into which the other ends of four suspensionwires 16A are inserted (see FIG. 8). Also, upper ring-shaped end section304A of magnet holder 30A has four wire insertion holes 304Aa into whichthe other ends of four suspension wires 16A are inserted (see FIG. 8).The other ends of four suspension wires 16A are inserted into four wirefixing holes 324Aa via these four wire insertion holes 304Aa, and arefixed with adhesive, solder, or the like.

Four suspension wires 16A are used to supply current to first and secondfocusing coils 26A-1 and 26A-2.

As described above, permanent magnet 28A comprises four first permanentmagnet sections 282A-1 and four second permanent magnet sections 282A-2disposed so as to face each other in first direction (front-backdirection) X and second direction (horizontal direction) Y, and to bespaced vertically in the optical axis O direction.

Camera-shake correction apparatus 10A is provided with onesquare-ring-shaped coil board 40A disposed so as to be inserted betweenand spaced from four first permanent magnet sections 282A-1 and foursecond permanent magnet sections 282A-2. Coil board 40A hasthrough-holes 40Aa at its four corners for the passage of foursuspension wires 16A. Above camera-shake correction coils 18A are formedon this one coil board 40A.

To be precise, four camera-shake correction coils 18Af, 18Ab, 18A1, and18Ar are formed on coil board 40A as camera-shake correction coils 18A(see FIG. 9).

Two camera-shake correction coils 18Af and 18Ab disposed so as to faceeach other in first direction (front-back direction) X are for moving(rocking) auto-focusing lens drive apparatus 20A in first direction(front-back direction) X. These two camera-shake correction coils 18Afand 18Ab are referred to as the first-direction actuator. Here,camera-shake correction coil 18Af located forward with respect tooptical axis O is referred to as the “front camera-shake correctioncoil,” and camera-shake correction coil 18Ab located rearward withrespect to optical axis O is referred to as the “back camera-shakecorrection coil.”

On the other hand, two camera-shake correction coils 18A1 and 18Ardisposed so as to face each other in second direction (horizontaldirection) Y are for moving (rocking) auto-focusing lens drive apparatus20A in second direction (horizontal direction) Y. These two camera-shakecorrection coils 18A1 and 18Ar are referred to as the second-directionactuator. Here, camera-shake correction coil 18A1 located leftward withrespect to optical axis O is referred to as the “left camera-shakecorrection coil,” and camera-shake correction coil 18Ar locatedrightward with respect to optical axis O is referred to as the “rightcamera-shake correction coil.”

In any event, four camera-shake correction coils 18Af, 18Ab, 18A1, and18Ar are for driving the entirety of auto-focusing lens drive apparatus20A in the X-axis direction (first direction) and Y-axis directionsecond direction) in collaboration with permanent magnet 28A. Also, thecombination of four camera-shake correction coils 18Af, 18Ab, 18A1, and18Ar and permanent magnet 28A functions as a voice coil motor (VCM).

Thus, camera-shake correction apparatus 10A illustrated corrects camerashake by moving lens barrel 12A itself, housed in auto-focusing lensdrive apparatus 20A, in first direction (front-back direction) X andsecond direction (horizontal direction) Y. Therefore, camera-shakecorrection apparatus 10A is referred to as a “barrel-shifting”camera-shake correction apparatus.

Camera-shake correction apparatus 10A is also provided with cover 42Athat includes square tubular section 422A covering the upper part (fourfirst permanent magnet sections 282A-1) of auto-focusing lens driveapparatus 20A.

Camera-shake correction apparatus 10A illustrated is also provided withposition detection section 50A for detecting the position ofauto-focusing lens drive apparatus 20A with respect to base 14A.Position detection section 50A illustrated comprises a magnetic positiondetection section composed of two Hall devices 50A mounted on basesection 142A of base 14A. These two Hall devices 50A are disposed facingand spaced from two of four second permanent magnet sections 282A-2. Asshown in FIG. 10, Hall devices 50A are disposed so as to intersect thedirection from the N pole to the S pole in second permanent magnetsections 282A-2.

One Hall device 50A disposed in first direction (front-back direction) Xwith respect to optical axis O detects a first position associated withfirst direction (front-back direction) X movement (rocking) by detectingmagnetic force of one second permanent magnet section 282A-2 facing it.One Hall device 50A disposed in second direction (horizontal direction)Y with respect to optical axis O detects a second position associatedwith second direction (horizontal direction) Y movement (rocking) bydetecting magnetic force of one second permanent magnet section 282A-2facing it.

In camera-shake correction apparatus 10A according to the secondembodiment, a magnetic position detection section comprising two Halldevices 50A is used as position detection section 50A, but a magneticposition detection section comprising four Hall devices 50 may also beused. as in camera-shake correction apparatus 10 according to the firstembodiment described earlier.

A magnetic circuit used in camera-shake correction apparatus 10A shownin FIG. 6 and FIG. 7 will now be described in detail with reference toFIG. 9 through FIG. 11. FIG. 9 is an oblique view of the magneticcircuit, and FIG. 10 is a vertical cross-sectional view of the magneticcircuit. FIG. 11 is a plan view with four first permanent magnetsections 282A-2 and first focusing coil 26A-1 omitted from the magneticcircuit.

Four first permanent magnet sections 282A-1 and four second permanentmagnet sections 282A-2 have different adjacent pole magnetization inoutward and inward radial directions of lens holder 24A. For example, asshown in FIG. 10, first permanent magnet sections 282A-1 have inward Spole magnetization and outward N pole magnetization, while four secondpermanent magnet sections 282A-2 have outward S pole magnetization andinward N pole magnetization. The arrows in FIG. 10 indicate thedirections of magnetic flux generated by these permanent magnet sections282A-1 and 282A-2.

Operation when the position of lens holder 24A (lens barrel 12A) isadjusted in the optical axis O direction will now be described withreference to FIG. 9.

A first AF current and second AF current flow in different directionsfrom each other in first focusing coil 26A-1 and second focusing coil26A-2 respectively. For example, as shown in FIG. 9, in first focusingcoil 26A-1, a first AF current flows in a clockwise direction asindicated by arrow I.sub.AF1, and in second focusing coil 26A-2, asecond AF current flows in a counterclockwise direction as indicated byarrow I.sub.AF2.

As shown in FIG. 9, in this case, according to Fleming's left hand rule,an upward magnetic force acts on first focusing coil 26A-1 as indicatedby arrow F.sub.AF1, and an upward magnetic force also acts on secondfocusing coil 26A-2 as indicated by arrow F.sub.AF2. As a result, lensholder 24A (lens barrel 12A) can be moved in the upward optical axis Odirection.

Conversely, by passing a first AF current through first focusing coil26A-1 in a counterclockwise direction, and passing a second AF currentthrough second focusing coil 26A-2 in a clockwise direction, lens holder24A (lens barrel 12A) can be moved in the downward optical axis Odirection.

Operation when the entirety of auto-focusing lens drive apparatus 20A ismoved in first direction (front-back direction) X or second direction(horizontal direction) Y will now be described with reference to FIG.11.

First, operation when the entirety of auto-focusing lens drive apparatus20A is moved in second direction (horizontal direction) Y will bedescribed. In this case, as shown in FIG. 11, in left camera-shakecorrection coil 18A1 a first camera-shake correction (IS) current flowsin a clockwise direction as indicated by arrow I.sub.IS1, and in rightcamera-shake correction coil 18Ar a second camera-shake correction (IS)current flows in a counterclockwise direction as indicated by arrowI.sub.IS2.

In this case, according to Fleming's left hand rule, a left-directionmagnetic force acts on left camera-shake correction coil 18A1, and aleft-direction magnetic force also acts on right camera-shake correctioncoil 18Ar. However, since these camera-shake correction coils 18A1 and18Ar are fixed to base 14A, as a reaction thereto, right-directionmagnetic forces as indicated by arrows F.sub.IS1 and F.sub.IS2 in FIG.11 act on the entirety of auto-focusing lens drive apparatus 20A. As aresult, the entirety of auto-focusing lens drive apparatus 20A can bemoved in a rightward direction.

Conversely, by passing a first IS current through left camera-shakecorrection coil 18A1 in a counterclockwise direction, and passing asecond IS current through right camera-shake correction coil 18Ar in aclockwise direction, the entirety of auto-focusing lens drive apparatus20A can be moved in a leftward direction.

On the other hand, by passing a third IS current through backcamera-shake correction coil 18Ab in a clockwise direction, and passinga fourth IS current through front camera-shake correction coil 18Af in acounterclockwise direction, the entirety of auto-focusing lens driveapparatus 20A can be moved in a forward direction.

Also, by passing a third IS current through back camera-shake correctioncoil 18Ab in a counterclockwise direction, and passing a fourth IScurrent through front camera-shake correction coil 18Af in a clockwisedirection, the entirety of auto-focusing lens drive apparatus 20A can bemoved in a rearward direction.

In this way, camera shake can be corrected.

Camera-shake correction apparatus 10A according to a second embodimentof the present invention as described above achieves the followingeffects.

Since auto-focusing lens drive apparatus 20A is provided withcamera-shake correction apparatus 10A, and permanent magnet 28A is usedin common, the number of component parts can be reduced. As a result,the size (mainly the height) of camera-shake correction apparatus 10Acan be made smaller (lower).

In an optical unit tilting type of camera-shake correction apparatus,there is a rotation shaft, and consequently friction occurs between ahole and shaft, resulting in the occurrence of hysteresis. In contrast,in camera-shake correction apparatus 10A according to this secondembodiment, the entirety of auto-focusing lens drive apparatus 20A issupported mechanically by four suspension wires 16A, making hysteresisunlikely to occur.

Compared with camera-shake correction apparatuses using conventionaloptical camera-shake correction methods (lens shifting, sensor shifting,or optical unit tilting). the use of a barrel-shifting method enablesthe size (mainly the height) of camera-shake correction apparatus 10A tobe made virtually the same that of auto-focusing lens drive apparatus20A. As a result, it is possible for camera-shake correction apparatus10A according to this second embodiment to be installed in an opticalcamera-shake correcting camera for mobile phone use.

Also, since camera-shake correction coils 18A are disposed between upperfour first permanent magnet sections 282A-1 and lower four secondpermanent magnet sections 282A-2, it is possible to implement highlysensitive actuators.

In this second embodiment, a magnetic position detection sectioncomprising two Hall devices 50A is used as a position detection section(position sensor), but another position detection section (positionsensor) such as a photoreflector or suchlike optical position detectionsection may be used instead of Hall devices 50A.

In the above-described second embodiment, permanent magnet 28A comprisesfour first permanent magnet sections 282A-1 and four second permanentmagnet sections 282A-2 disposed so as to face each other in firstdirection X and second direction Y, and to be spaced vertically in theoptical axis O direction, but the number of first permanent magnetsections and second permanent magnet sections is not limited to foureach, and, for example, eight sections may be used that are disposedfacing in diagonal directions rather than in only a first and seconddirection. In this case, the number of camera-shake correction coils 18Ais also changed to eight. Also, in the above-described secondembodiment, four suspension wires 16A rise up from the four corners ofbase section 142A of base 14A, but these ends may also rise up from theouter periphery of base section 142A. Furthermore, the number ofsuspension wires 16A is not limited to four, and may be any plurality.

Camera-shake correction apparatuses 10 and 10A according to the firstand second embodiments described above use a “moving magnet method” inwhich permanent magnets 18 and 18A are moved. However, a “moving coilmethod” in which a coil is moved may also be used. By this means, movingparts of an auto-focusing lens drive apparatus can be made lighter.

Camera-shake correction apparatus 10B according to a third embodiment ofthe present invention will now be described with reference to FIG. 12through FIG. 15. FIG. 12 is an external oblique view of camera-shakecorrection apparatus 10B. FIG. 13 is a vertical cross-sectional view ofcamera-shake correction apparatus 10B. FIG. 14 is an exploded obliqueview of camera-shake correction apparatus 10B. FIG. 15 is an explodedoblique view of auto-focusing lens drive apparatus 20B used incamera-shake correction apparatus 10B shown in FIG. 12.

Here, orthogonal coordinate system (X,Y,Z) is used, as shown in FIG. 12through FIG. 15. In the states illustrated in FIG. 12 through FIG. 15,in orthogonal coordinate system (X,Y,Z), the X-axis direction is thefront-back direction (depth direction), the Y-axis direction is thehorizontal direction (width direction), and the Z-axis direction is thevertical-direction (height direction). In the examples shown in FIG. 12through FIG. 15, vertical direction Z is the lens optical axis Odirection. In this third embodiment, the X-axis direction (front-backdirection) is also referred to as the first direction, and the Y-axisdirection (horizontal direction) is also referred to as the seconddirection.

In an actual usage situation, the optical axis O direction—that is, theZ-axis direction—is the front-back direction. In other words, the upwardZ-axis direction is the forward direction, and the downward Z-axisdirection is the rearward direction.

Camera-shake correction apparatus 10B illustrated is an apparatus thatcorrects camera shake (vibration) that occurs when a still image iscaptured with a small camera for mobile phone use, and enables ablur-free image to be captured. Camera-shake correction apparatus 10Bcorrects camera shake by moving a moving part of auto-focusing lensdrive apparatus 20B in first direction (front-back direction) X andsecond direction (horizontal direction) Y that are perpendicular tooptical axis O and are perpendicular to each other. Camera-shakecorrection apparatus 10B illustrated is a camera-shake correctionapparatus that uses a “moving coil method.”

Auto-focusing lens drive apparatus 20B is for moving a lens barrel (notillustrated) along optical axis O. Base 14B is disposed so as to bespaced from the bottom surface of auto-focusing lens drive apparatus 20Bin an outward radial direction. Although not illustrated, an imagingdevice disposed on an imaging board is mounted on the bottom (rear part)of this base 14B. This imaging device captures a subject image formed bymeans of the lens barrel, and converts this subject image to anelectrical signal. The imaging device comprises, for example, a CCD(charge coupled device) image sensor, CMOS (complementary metal oxidesemiconductor) image sensor, or the like. Therefore, a camera module isconfigured by combining lens drive apparatus 20B, an imaging board, andan imaging device.

Base 14B comprises ring-shaped base section 142B of square externalshape and having a circular aperture inside, and square-tube-shapedtubular section 144B having four rectangular apertures 144Ba thatprojects in the upward optical axis O direction from the outer edge ofthis base section 142B.

Camera-shake correction apparatus 10B has eight suspension wires 16B,pairs of which each have one end fixed to one of the four corners ofbase section 142B of base 14B, and camera-shake correction coils 18Bdisposed so as to face permanent magnet 28B of auto-focusing lens driveapparatus 20B described later herein in a manner described later herein.

Eight suspension wires 16B extend along optical axis O, and support amoving part of auto-focusing lens drive apparatus 20B so as to be ableto rock in first direction (front-back direction) X and second direction(horizontal direction) Y. The other ends of eight suspension wires 16Bare fixed to the upper end of above auto-focusing lens drive apparatus20B as described later herein.

As described later herein, camera-shake correction apparatus 10B isprovided with one square-ring-shaped coil board 40B disposed so as toface and be spaced from permanent magnet 28B. This coil board 40B isattached to coil holder 44B. Above camera-shake correction coils 18B areformed on this coil board 40B.

Coil holder 44B has four pillar sections 442B extending in parallel tothe optical axis O direction at its four corners, approximately squareupper ring-shaped end 444B attached to the upper ends (front ends) ofthese four pillar sections 442B, and lower ring-shaped end 446B attachedto the lower ends (rear ends) of four pillar sections 442B. Upperring-shaped end 444B has four upper projections 444Ba projecting upwardat its four corners, and lower ring-shaped end 446B also has four lowerprojections 446Ba projecting upward.

Auto-focusing lens drive apparatus 208 will now be described withreference to FIG. 14 and FIG. 15.

Auto-focusing lens drive apparatus 20B is provided with lens holder 24Bhaving tubular section 240B for holding a lens barrel, first and secondfocusing coils 26B-1 and 26B-2 fixed to this lens holder 24B so as to bepositioned around tubular section 240B, four magnet holders 30B thathold permanent magnet 28B disposed on the outside of first and secondfocusing coils 26B-1 and 26B-2, facing first and second focusing coils26B-1 and 26B-2, and a pair of leaf springs 32B and 34B provided oneither side of optical axis O of tubular section 240B of lens holder24B.

First focusing coil 26B-1 is installed in the upper optical axis Odirection of tubular section 240B of lens holder 24B, and secondfocusing coil 26B-2 is installed in the lower optical axis O directionof tubular section 240B of lens holder 24B.

The pair of leaf springs 32B and 34B support lens holder 24B so as to bedisplaceable in the optical axis O direction when lens holder 24B ispositioned in a radial direction. Of the pair of leaf springs 32B and34B, leaf spring 32B is referred to as the upper leaf spring, and leafspring 34B is referred to as the lower leaf spring.

As stated above, in an actual usage situation, the upward Z-axisdirection (optical axis O direction) is the forward direction, and thedownward Z-axis direction (optical axis O direction) is the rearwarddirection. Therefore, upper leaf spring 32B is also referred to as thefront spring, and lower leaf spring 34B is also referred to as the rearspring.

Four magnet holders 30B are inserted into and fixed in four rectangularapertures 144Ba of tubular section 144B of base 14B. Permanent magnet28B comprises eight rectangular permanent magnet sections disposed inpairs on four magnet holders 30B so as to be spaced from each other infirst direction (front-back direction) X, second direction (horizontaldirection) Y, and vertical direction Z. Of these eight rectangularpermanent magnet sections, four first permanent magnet sections 282B-1are disposed in the upper optical axis O direction of four magnetholders 30B, and remaining four second permanent magnet sections 282B-2are disposed in the lower optical axis O direction of four magnetholders 30B. Four first permanent magnet sections 282B-1 are disposedspaced from first focusing coil 26B-1, and four second permanent magnetsections 282B-2 are disposed spaced from second focusing coil 26B-2.

Upper leaf spring (front spring) 32B is disposed above (forward) in theoptical axis O direction in lens holder 24B, and lower leaf spring (rearspring) 34B is disposed below (rearward) in the optical axis O directionin lens holder 24B. Upper leaf spring (front spring) 32B and lower leafspring (rear spring) 34B have almost identical configurations.

Upper leaf spring (front spring) 32B has upper inner ring section 322Aattached to the top of lens holder 24B, and upper outer ring section324B attached to upper ring-shaped end 444B of coil holder 44B. Fourupper arm sections 326B are provided between upper inner ring section322B and upper outer ring section 324B. That is to say, four upper armsections 326B link upper inner ring section 322B and upper outer ringsection 324B.

Upper outer ring section 324B has four upper holes 324Ba into which fourupper projections 444Ba of coil holder 44B are pressed (inserted andattached). That is to say, four upper projections 444Ba of coil holder44B are pressed into (inserted into and attached inside) four upperholes 324Ba of upper outer ring section 324B of upper leaf spring 32B.On the other hand, tubular section 240B of lens holder 24B has fourupper projections 240Ba on its upper end. Upper inner ring section 322Bhas four upper holes 322Ba into which these four upper projections 240Baof tubular section 240B are pressed (inserted and attached). That is tosay, four upper projections 240Ba of tubular section 240B of lens holder24B are pressed into (inserted into and attached inside) four upperholes 322Ba of upper inner ring section 322B of upper leaf spring 32B.

Similarly, lower leaf spring (rear spring) 34B has lower inner ringsection 342B attached to the bottom of lens holder 24B, and lower outerring section 344B attached to lower ring-shaped end 446B of coil holder44B. Four lower arm sections 346B are provided between lower inner ringsection 342B and upper outer ring section 344B. That is to say, fourlower arm sections 346B link lower inner ring section 342B and lowerouter ring section 344B.

Lower outer ring section 344B has four lower holes 344Ba into which fourlower projections 446Ba of coil holder 44B are pressed (inserted andattached). That is to say, four lower projections 446Ba of coil holder44B are pressed into (inserted into and attached inside) four lowerholes 344Ba of lower outer ring section 344B of lower leaf spring 34B.

The elastic members comprising upper leaf spring 32B and lower leafspring 34B function as guide sections that guide lens holder 24B so asto be able to move only in the optical axis O direction. Upper leafspring 32B and lower leaf spring 34B are made of beryllium copper,phosphor bronze, or the like.

An internal thread (not illustrated) is cut into the inner peripheralwall of tubular section 240B of lens holder 24B, and an external thread(not illustrated) that is screwed into the above internal thread is cutinto the outer peripheral wall of the lens barrel. Therefore, to fit thelens barrel into lens holder 24B, the lens barrel is accommodated insidelens holder 24B by turning the lens barrel about optical axis O andscrewing the lens barrel into tubular section 240B of lens holder 24B inthe optical axis O direction, and they are joined together by means ofadhesive or the like.

By passing first and second auto-focusing (AF) currents through firstand second focusing coils 26B-1 and 26B-2 respectively, it is possibleto adjust the position of lens holder 24B (the lens barrel) in theoptical axis O direction through the mutual action of the magnetic fieldof permanent magnet 28B and magnetic fields by the first and second AFcurrents flowing through first and second focusing coils 26B-1 and26B-2.

Camera-shake correction apparatus 10B will now be described in furtherdetail with reference to FIG. 13 and FIG. 14.

As stated earlier, camera-shake correction apparatus 10B has eightsuspension wires 16B, pairs of which each have one end fixed to one ofthe four corners of base section 142B of base 14B, and camera-shakecorrection coils 188 disposed so as to face permanent magnet 28B ofabove-described auto-focusing lens drive apparatus 20B.

Consequently, base section 142B has eight wire fixing holes 142Ba,disposed in pairs in its four corners, into each of which one end of oneof eight suspension wires 16B is inserted.

Eight suspension wires 16B extend along optical axis O, and support amoving part of auto-focusing lens drive apparatus 20B so as to be ableto rock in first direction (front-back direction) X and second direction(horizontal direction) Y. The other ends of eight suspension wires 16Bare fixed to the top of above auto-focusing lens drive apparatus 20B.

To be precise, coil holder 44B further has four projecting sections 448Bprojecting in an outward radial direction at the four corners of upperring-shaped end 444B (see FIG. 15). Each of four projecting sections448B has two wire fixing holes 448Ba into which the other ends of twosuspension wires 16B are inserted. Therefore, the other ends of eightsuspension wires 16B are inserted into these eight wire fixing holes448Ba, and are fixed with adhesive, solder, or the like.

The reason why the number of suspension wires 16B is eight in this thirdembodiment is that current is supplied to first and second focusingcoils 268-1 and 26B-2, and camera-shake correction coils 18B, via theseeight suspension wires 16B.

As stated above, permanent magnet 28B comprises four first permanentmagnet sections 282B-1 and four second permanent magnet sections 282B-2disposed so as to face each other in first direction (front-backdirection) X and second direction (horizontal direction) Y, and so as tobe spaced vertically in the optical axis O direction.

Camera-shake correction apparatus 10B is provided with one ring-shapedcoil board 40B disposed so as to be inserted between and spaced fromfour first permanent magnet sections 282B-1 and four second permanentmagnet sections 282B-2. Above camera-shake correction coils 18B areformed on this one coil board 40B.

To be precise, four camera-shake correction coils 18B are formed on coilboard 40B.

Two camera-shake correction coils 18B disposed so as to face each otherin first direction (front-back direction) X are for moving (rocking) amoving part of auto-focusing lens drive apparatus 20B in first direction(front-back direction) X. These two camera-shake correction coils 18Bare referred to as the first-direction actuator.

On the other hand, two camera-shake correction coils 18B disposed so asto face each other in second direction (horizontal direction) Y are formoving (rocking) a moving part of auto-focusing lens drive apparatus 20Bin second direction (horizontal direction) Y. These two camera-shakecorrection coils 18B are referred to as the second-direction actuator.

In any event, camera-shake correction coils 18B are for driving a movingpart of auto-focusing lens drive apparatus 20B in the X-axis direction(first direction) and Y-axis direction second direction) incollaboration with permanent magnet 28B. Also, the combination ofcamera-shake correction coils 18B and permanent magnet 28B functions asa voice coil motor (VCM).

Thus, camera-shake correction apparatus 10B illustrated corrects camerashake by moving the lens barrel itself, housed in auto-focusing lensdrive apparatus 20B, in first direction (front-back direction) X andsecond direction (horizontal direction) Y. Therefore, camera-shakecorrection apparatus 10B is referred to as a “barrel-shifting”camera-shake correction apparatus.

Camera-shake correction apparatus 10B is also provided with cover 42covering the upper part of auto-focusing lens drive apparatus 20B.

Also, referring to FIG. 16 in addition to FIG. 13 and FIG. 14,camera-shake correction apparatus 10B is also provided with positiondetection section (50B, 51B) for detecting the position of a moving partof auto-focusing lens drive apparatus 20B with respect to base 14B.

To be precise, position detection section (50B, 51B) illustratedcomprises an optical position detection section. Position detectionsection (50B, 51B) comprises two position detectors, each of whichcomprises photoreflector 50B and position information section 51Bdisposed facing each other. Two position information sections 51B aredisposed in first direction X and second direction Y on the underside oflower ring-shaped end 446B of coil holder 44B (in FIG. 13, only oneposition information section disposed in second direction Y isillustrated).

As shown in FIG. 16, each position information section 51B comprisesreflective tape (a reflective seal), and is affixed to the underside oflower ring-shaped end 446B. Reflective tape 51B has a pattern in which areference position is made a boundary in first direction X or seconddirection Y, and black and white/light and dark are clearlydistinguishable.

On the other hand, two photoreflectors 50B are mounted on base section142B of base 14B as shown in FIG. 14. Two photoreflectors 50B aredisposed spaced from and facing two position information sections 51B.

One photoreflector 50B disposed in first direction (front-backdirection) X with respect to optical axis O detects a first positionassociated with first direction (front-back direction) X movement(rocking) as a voltage level by receiving reflected light from oneposition information section 51B (detecting the light intensity of thereflected light) by intersecting the light and dark of that positioninformation section 51B facing that photoreflector 50B, as shown by thearrow in FIG. 16. One photoreflector 50B disposed in second direction(horizontal direction) Y with respect to optical axis O detects a secondposition associated with second direction (horizontal direction) Ymovement (rocking) as a voltage level by receiving reflected light fromone position information section 51B (detecting the light intensity ofthe reflected light) by intersecting the light and dark of that positioninformation section 51B facing that photoreflector 50B, as shown by thearrow in FIG. 16.

In camera-shake correction apparatus 10B according to the thirdembodiment, an optical position detection section that includes twophotoreflectors 50B is used as position detection section 50B, but anoptical position detection section that includes four photoreflectorsmay also be used. Also, the position information section 51B pattern isnot limited to a black-and-white light-and-dark (binary) pattern, andvarious kinds of patterns may be used, such as a continuous patternusing gradations, or a continuous pattern using area ratio variation.

In camera-shake correction apparatus 10B having this kind ofconfiguration, operation when the position of lens holder 24B (the lensbarrel) is adjusted in the optical axis O direction is similar to thatof camera-shake correction apparatus 10A according to the secondembodiment described with reference to FIG. 9, and therefore adescription thereof is omitted here. Also, operation when a moving partof auto-focusing lens drive apparatus 20B is moved in first direction(front-back direction) X or second direction (horizontal direction) Y issimilar to that of camera-shake correction apparatus 10A according tothe second embodiment described with reference to FIG. 11, and thereforea description thereof is omitted here.

Camera-shake correction apparatus 10B according to a third embodiment ofthe present invention as described above achieves the following effects.

Since auto-focusing lens drive apparatus 20B is provided withcamera-shake correction apparatus 10B, and permanent magnet 28B is usedin common, the number of component parts can be reduced. As a result,the size (mainly the height) of camera-shake correction apparatus 10Bcan be made smaller (lower).

In an optical unit tilting type of camera-shake correction apparatus,there is a rotation shaft, and consequently friction occurs between ahole and shaft, resulting in the occurrence of hysteresis. In contrast,in camera-shake correction apparatus 10B according to this thirdembodiment, a moving part of auto-focusing lens drive apparatus 20B issupported mechanically by eight suspension wires 16B, making hysteresisunlikely to occur.

Compared with camera-shake correction apparatuses using conventionaloptical camera-shake correction methods (lens shifting, sensor shifting,or optical unit tilting), the use of a barrel-shifting method enablesthe size (mainly the height) of camera-shake correction apparatus 10B tobe made virtually the same that of auto-focusing lens drive apparatus20B. As a result, it is possible for camera-shake correction apparatus10B according to this third embodiment to be installed in an opticalcamera-shake correcting camera for mobile phone use.

Also, since camera-shake correction coils 18B are disposed between upperfour first permanent magnet sections 282B-1 and lower four secondpermanent magnet sections 282B-2, it is possible to implement highlysensitive actuators.

Furthermore, since a moving coil method is used, a moving part ofauto-focusing lens drive apparatus 20B can be made lighter than when amoving magnet method is used.

To be precise, in “moving-magnet” camera-shake correction apparatus 10Aaccording to the second embodiment, the entirety of auto-focusing lensdrive apparatus 20B operates as a moving part. That is to say, as shownin FIG. 8, moving-part component parts comprise lens barrel 12A, lensholder 24A, first and second focusing coils 26A-1 and 26A-2, upper leafspring 32A, lower leaf spring 34A, permanent magnet 28A, and magnetholder 30A. Consequently, the total weight of moving parts when using amoving magnet method is, for example, 1620 mg.

In contrast, in “moving-coil” camera-shake correction apparatus 10Baccording to the third embodiment, as shown in FIG. 15, moving-partcomponent parts comprise the lens barrel, lens holder 24B, first andsecond focusing coils 26B-1 and 26B-2, camera-shake correction coils18B, and coil holder 44B. Consequently, the total weight of moving partswhen using a moving coil method is, for example, 765 mg.

Since the weight of moving parts can be reduced in this way, an offsetcorrection current value can be improved, and as a result, the thrust ofmoving parts can be increased.

In the above-described third embodiment, permanent magnet 28B comprisesfour first permanent magnet sections 282B-1 and four second permanentmagnet sections 282B-2 disposed so as to face each other in firstdirection X and second direction Y, and to be spaced vertically in theoptical axis O direction, but the number of first permanent magnetsections and second permanent magnet sections is not limited to foureach, and, for example, eight sections may be used that are disposedfacing in diagonal directions rather than in only a first and seconddirection. In this case, the number of camera-shake correction coils 18Bis also changed to eight. Also, in the above-described third embodiment,eight suspension wires 16B rise up in pairs from the four corners ofbase section 142B of base 14B, but these ends may also rise up in pairsfrom the outer periphery of base section 142B. Furthermore, the numberof suspension wires 16B is not limited to eight, and may be anyplurality.

FIG. 17 is a vertical cross-sectional view of a sample variant in whichthe optical position detection section used in camera-shake correctionapparatus 10B according to the above-described third embodiment is usedas a position detection section in camera-shake correction apparatus 10Aaccording to the above-described second embodiment.

In this sample variant, two photoreflectors 50B are provided instead oftwo Hall devices 50A, in the positions in which two Hall devices 50Awere disposed. That is to say, these two photoreflectors 50B aredisposed spaced from and facing two of four second permanent magnetsections 282A-2. Two position information sections (pieces of reflectivetape) 51B are affixed to a moving part (auto-focusing lens driveapparatus 20A) facing these two photoreflectors 50B. In the exampleillustrated, two position information sections (pieces of reflectivetape) 51B are provided on (affixed to) the underside of tower leafspring 34A.

A position detection operation by this optical position detectionsection is similar to that of the third embodiment described earlier,and therefore a description thereof will be omitted here in order tosimplify the explanation.

Although not illustrated, an above-described optical position detectionsection may of course also be used instead of a magnetic positiondetection section in camera-shake correction apparatus 10 according tothe above-described first embodiment.

A typical aspect of the present invention is described below.

In a camera-shake correction apparatus according to a typical aspect ofthe present invention described above, an auto-focusing lens driveapparatus may be provided with: a lens holder that has a tubular sectionfor holding a lens barrel, and that fixes a focusing coil so as to bepositioned around the tubular section; a magnet holder that is disposedon the outer periphery of this lens holder and holds a permanent magnet;and a pair of leaf springs that support the lens holder so as to bedisplaceable in the optical axis direction when positioned in a radialdirection.

According to a camera-shake correction apparatus according to a firstaspect of the present invention, an auto-focusing lens drive apparatusmay have an upper board mounted on the upper end of a magnet holder. Inthis case, other ends of a plurality of suspension wires are fixed tothe upper board. Also, a pair of leaf springs may be fixed in linkedfashion between the lens holder and magnet holder. The permanent magnetmay include a plurality of permanent magnet sections disposed so as toface each other in a first direction and second direction. In this case,a camera-shake correction coil is disposed on the outside of theplurality of permanent magnet sections, the camera-shake correctionapparatus may be provided with a plurality of coil boards that aredisposed so as to face and be spaced from the plurality of permanentmagnet sections, and on which a camera-shake correction coil is formed.The camera-shake correction apparatus may also include a shield coverthat covers the plurality of coil boards. in this case, the plurality ofcoil boards may be attached to the inner wall of the shield cover. It isdesirable for the camera-shake correction apparatus to have a positiondetection section for detecting the position of the auto-focusing lensdrive apparatus with respect to a base. The position detection sectionmay comprise, for example, a Hall device that is disposed so as to bespaced from and face the permanent magnet sections, and is mounted onthe base.

According to a camera-shake correction apparatus according to anotheraspect of the present invention, a permanent magnet may comprise aplurality of first permanent magnet sections and a plurality of secondpermanent magnet sections that are disposed so as to face each other ina first direction and second direction, and that are disposed so as tobe spaced from each other in the optical axis direction. The firstpermanent magnet sections and second permanent magnet sections arepolarized into an N pole and S pole in a radial direction, and the firstpermanent magnet sections and second permanent magnet sections havemagnetic poles that differ in the optical axis direction. Focusing coilscomprise a first and second focusing coil that are fixed so as to bepositioned around a tubular section of a lens holder, facing theplurality of first permanent magnet sections and the plurality of secondpermanent magnet sections respectively. A camera-shake correction coilcomprises a plurality of camera-shake correction coils that are disposedinserted between the plurality of first permanent magnet sections andfour second permanent magnet sections. The camera-shake correctionapparatus is provided with a ring-shaped coil board on which a pluralityof camera-shake correction coils are formed.

According to a camera-shake correction apparatus according to a secondaspect of the present invention, a base may comprise a ring-shaped basesection and a tubular section extending in an upward optical axisdirection from the outer edge of this base section. In this case, a coilboard is fixed to the upper end of the tubular section of the base, anda pair of leaf springs are fixed in linked fashion between a lens holderand magnet holder. Also, a plurality of suspension wires may rise upfrom the outer peripheral section of the base section. In this case, themagnet holder is provided with an upper ring-shaped end section, thisupper ring-shaped end section may have a plurality of wire insertionholes into which the other ends of the plurality of suspension wires areinserted, and of the pair of leaf springs, the upper leaf spring in theupper optical axis direction may have a plurality of wire fixing holesinto which the other ends of the plurality of suspension wires areinserted. The coil board may have a plurality of through-holes throughwhich the plurality of suspension wires pass. It is desirable for thecamera-shake correction apparatus to have a position detection sectionfor detecting the position of an auto-focusing lens drive apparatus withrespect to the base. The position detection section may comprise, forexample, two Hall devices that are disposed so as to be spaced from andface at least two second permanent magnet sections that are disposed ina first direction and second direction among a plurality of secondpermanent magnet sections, and that are mounted on the base section.Instead of this, the position detection section may comprise at leasttwo photoreflectors and at least two position information sections,disposed so as to face each other. In this case, at least two positioninformation sections are disposed in the first direction and seconddirection on the underside of the lower leaf spring positioned in alower optical axis direction among the pair of leaf springs, and atleast two photoreflectors are mounted on the base section, disposed soas to be spaced from and face at least two position information sectionsrespectively.

According to a camera-shake correction apparatus according to a thirdaspect of the present invention, the camera-shake correction apparatusis further provided with a coil holder that holds a coil board, and abase may comprise a ring-shaped base section and a tubular sectionhaving a plurality of apertures extending in an upward optical axisdirection from the outer edge of this base section. In this case, amagnet holder comprises a plurality of magnet holders that hold onefirst permanent magnet section and one second permanent magnet sectionrespectively. The plurality of magnet holders are fixedly inserted intoa plurality of apertures of the tubular section of the base, and a pairof leaf springs are fixed in linked fashion between a lens holder andthe coil holder. Also, a plurality of suspension wires may rise up fromthe outer peripheral section of the base section. In this case, the coilholder is provided with an upper ring-shaped end section and a pluralityof projecting sections that project in an outward radial direction fromthe outer peripheral section of this upper ring-shaped end section, andthis plurality of projecting sections may have a plurality of wirefixing holes into which the other ends of the plurality of suspensionwires are inserted. It is desirable for the camera-shake correctionapparatus to have a position detection section for detecting theposition of a moving part of an auto-focusing lens drive apparatus withrespect to the base. The coil holder is further provided with a lowerring-shaped end section, and the above position detection section maycomprise at least two photoreflectors and at least two positioninformation sections, disposed so as to face each other. In this case,at least two position information sections are disposed in a firstdirection and second direction on the underside of the lower ring-shapedend section of the coil holder, and at least two photoreflectors aremounted on the base section, disposed so as to be spaced from and faceat least two position information sections respectively.

The present invention has been described above with particular referenceto embodiments thereof, but the present invention is not limited tothese embodiments. It is understood that various variations andmodifications in form and detail may be possible by those skilled in theart without departing from the spirit and scope of the present inventionstipulated in the claims. For example, in the above embodiments, amagnetic position detection section comprising Hall devices or anoptical position detection section that includes photoreflectors is usedas a position detection section (position sensor), but another positiondetection section (position sensor) may also be used.

This application is entitled to and claims the benefit of JapanesePatent Application No. 2009-191619, filed on Aug. 21, 2009, and JapanesePatent Application No. 2010-158602, filed on Jul. 13, 2010, thedisclosures of which including the specifications, drawings andabstracts are incorporated herein by reference in their entirety.

What is claimed is:
 1. A lens drive apparatus for use in a small cameramodule, the lens drive apparatus comprising: an assembly that is formedby assembling a lens holder together with a magnet holder that holds amagnet; a first drive section that displaces the lens holder in adirection of an optical axis in collaboration with the magnet and afirst coil; and a second drive section that displaces the assembly infirst and second directions orthogonal to the optical axis and to eachother in collaboration with the magnet and a second coil, wherein: themagnet holder comprises a hollow part that accommodates the magnet at aposition where a first surface of the magnet faces the first coil and asecond surface of the magnet faces the second coil, and the first coiland the second coil are respectively disposed such that a direction ofthe first surface of the magnet facing the first coil and a direction ofthe second surface of the magnet facing the second coil are differentfrom each other.
 2. The lens drive apparatus for use in a small cameramodule according to claim 1, comprising: a Hall device that detects aposition of the magnet in the first direction and the second direction,wherein: the hollow part accommodates the magnet at a position facingall of the first coil, the second coil and the Hall device.
 3. The lensdrive apparatus for use in a small camera module according to claim 1,comprising: a base that is disposed so as to be spaced from theassembly; and a plurality of suspension wires each having a first endfixed to the base and a second end fixed to the assembly, the suspensionwires being configured to support the assembly such that the assembly isdisplaceable in the direction orthogonal to the optical axis.
 4. Thelens drive apparatus for use in a small camera module according to claim1, wherein the assembly includes a leaf spring that is attached to themagnet holder and supports the lens holder such that the lens holder isdisplaceable in the direction of the optical axis.
 5. The lens driveapparatus for use in a small camera module according to claim 1, whereinthe first coil is disposed around the lens holder.
 6. The lens driveapparatus for use in a small camera module according to claim 1, whereinthe second coil is attached to an inside of a housing that houses theassembly.
 7. The lens drive apparatus for use in a small camera moduleaccording to claim 1, comprising: a base that is disposed so as to bespaced from the assembly and has an aperture through which the opticalaxis passes in a displacement range of the optical axis resulting fromdisplacement of the assembly in the first direction and the seconddirection.
 8. A small camera module comprising: the lens drive apparatusfor use in a small camera module according to claim 1; and an imagingdevice that captures a subject image formed by means of a lens sectionheld by the lens holder.
 9. A camera comprising: the small camera moduleaccording to claim 8; and a control section that controls the smallcamera module.